“Only”—­I was careful to add—­“understand, I don’t rank him as a magician, or sorcerer; nothing like that.  I’d rather think that he’s merely in possession of a scientific secret, no more wonderful in itself than, say, wireless.  He’s merely got hold of it in advance of the others; that’s all.”

“Then you think that the woman, too, is human?”

“The Nervina?” I hesitated.  “Perhaps you know more of this part of the thing than I do.”

“I only know”—­slowly—­“that she came and told me that Harry was soon to call.  And somehow, I never felt jealous of her, Hobart.”  Then she added:  “At the same time, I can understand that Harry might—­might have fallen in love with her.  She—­she was very beautiful.”

Charlotte is a brave girl.  She kept her voice as steady as my own.

We next discussed the disappearance of Chick Watson.  These details are already familiar to the reader of Harry’s story; likewise what happened to Queen, his Australian shepherd.  Like the other vanishings, it was followed by a single stroke on that prodigious, invisible bell—­what Harry calls “The Bell of the Blind Spot.”  And he has already mentioned my opinion, that this phenomenon signifies the closing of the portal of the unknown—­the end of the special conditions which produce the bluish spot on the ceiling, the incandescent streak of light, and the vanishing of whoever falls into the affected region.  The mere fact that no trace of the bell ever was found has not shaken my opinion.

And thus we reached the final disappearance, that which took away Harry.  Charlotte contrived to keep her voice as resolute as before, as she said: 

“He and the Nervina vanished together.  I turned round just as she rushed in, crying out, ’I can’t let you go alone!  I’ll save you, even beyond.’  That’s all she said, before—­it happened.”

“You saw nothing of the Rhamda then?”

“No.”

And we had neither seen nor heard of him since.  Until we got in touch with him, one important clue as to Harry’s fate was out of our reach.  There remained to us just one thread of hope—­the ring, which Charlotte was now wearing on her finger.

I lit a match and held it to the face of the gem.  As happened many times before, the stone exhibited its most astounding quality.  As soon as faintly heated, the surface at first clouded, then cleared in a curious fashion, revealing a startling distinct, miniature likeness of the four who had vanished into the Blind Spot.

I make no attempt to explain this.  Somehow or other, that stone possesses a telescopic quality which brings to a focus, right in front of the beholder’s eyes, a tiny “close-up” of our vanished friends.  Also, the gem magnifies what it reveals, so that there is not the slightest doubt that Dr. Holcomb, Chick Watson, Queen and Harry Wendel are actually reproduced—­I shall not say, contained—­ in that gem.  Neither shall I say that they are reflected; they are simply reproduced there.